[PATCH v16 2/9] irqchip: Add RISC-V incoming MSI controller early driver

[Eric Cheng]

On 4/19/2024 11:44 AM, Anup Patel wrote:
> On Fri, Apr 19, 2024 at 8:53 AM Eric Cheng <eric.cheng.linux at gmail.com> wrote:
>>
>> On 3/7/2024 10:03 PM, Anup Patel wrote:
>>
>>> +static int __init imsic_parse_fwnode(struct fwnode_handle *fwnode,
>>> +                                  struct imsic_global_config *global,
>>> +                                  u32 *nr_parent_irqs,
>>> +                                  u32 *nr_mmios)
>>> +{
>>
>> ...
>>
>>> +     /*
>>> +      * Find first bit position of group index.
>>> +      * If not specified assumed the default APLIC-IMSIC configuration.
>>> +      */
>>> +     rc = of_property_read_u32(to_of_node(fwnode), "riscv,group-index-shift",
>>> +                               &global->group_index_shift);
>>> +     if (rc)
>>> +             global->group_index_shift = IMSIC_MMIO_PAGE_SHIFT * 2;
>>> +
>>> +     /* Find number of interrupt identities */
>>> +     rc = of_property_read_u32(to_of_node(fwnode), "riscv,num-ids",
>>> +                               &global->nr_ids);
>>
>> Will here check if the pass-in interrupt identity number is (multi-64 -1) &&
>> between [63, 2047]?
>> Per spec AIA v1.0, Sec. 3.1 Interrupt files and interrupt identities:
>> "The number of interrupt identities supported by an interrupt file (and hence
>> the number of active
>> bits in each array) is one less than a multiple of 64, and may be a minimum of
>> 63 and a maximum
>> of 2047."
> 
> There is already a check on global->nr_ids to ensure the above is satisfied.
> Please see further below in imsic_parse_fwnode() function.
> 

Right, thanks.
>>
>>> +     if (rc) {
>>> +             pr_err("%pfwP: number of interrupt identities not found\n", fwnode);
>>> +             return rc;
>>> +     }
>>> +
>> ...
>>
>>
> 
> Regards,
> Anup